Regan appeals to the benefit of the doubt as a reason to include some animals within the scope of his arguments about the rights of animals. I think the informal appeal to the benefit of the doubt can be fleshed out and made more compelling. What I shall do differs from his project, however. It is narrower in scope, because I shall focus on a single issue, the dietary use of animals. On another dimension, though, I aim to do more. Regan thinks that it is “not unreasonable” to extend the benefit of the doubt, and that it is better to do so. I shall be arguing that it is unreasonable not to do so.